Factor out windmill check in shape patch generation

[ExE-Boss]

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Since https://github.com/tobspr/shapez.io/issues/1444 (PR https://github.com/tobspr/shapez.io/pull/1445) was rejected, this moves that code into a method to allow mods to change how many windmill sub‑shapes are allowed to spawn, and also limit any custom mod sub‑shapes that are allowed to spawn in the world, without replacing the entire internalGenerateShapePatch(rng, shapePatchSize, distanceToOriginInChunks) method.